Analysis of transient electrical field of barrier system of bushing outlet in converter transformer

This paper presents the characteristics of electric field under direct current polarity reversal voltage in the barrier system of bushing outlet in converter transformer. In the calculation of the transient electric field, the permittivity ε and conductivity γ of the dielectrics in the insulation structure are taking into account and the space and time discretization for governing equation in the finite element analysis are presented. The effects which different γ and voltage reversal time intervals have on the electric field distribution are examined under polarity reversal voltage (PR), changing from one steady state to another.